This article has been archived. It is offered "as is" and will no longer be updated.

This article has been archived. It is offered "as is" and will no longer be updated.

Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

If you are a Small Business customer, find additional troubleshooting and learning resources at the Support for Small Business site.

You configure Kerberos authentication between the front-end
and back-end servers that are running Microsoft Exchange Server 2003. In this
configuration, the following event is logged in the Application log on the
front-end server:

Event Type: WarningEvent Source:
EXPROXEvent Category: NoneEvent ID: 1000Date:
DateTime:
TimeUser: N/AComputer:
Front-end_Server_NameDescription: Microsoft
Exchange Server has detected that NTLM-based authentication is presently being
used between this server and server
'Back-end_Server_Name'. NTLM is still a secure
authentication mechanism and protects users' credentials. However, this
indicates that there may be a configuration issue preventing the use of
Kerberos authentication. If this condition persists, please verify that both
this server and server 'Back-end_Server_Name' are
properly configured to use Kerberos authentication. After applying any changes
it may be necessary to restart Internet Information Services on both the
front-end and back-end servers. As a result the authentication protocol fails
back to NTLM.

This event indicates that NTLM authentication is being
used instead of Kerberos authentication between the front-end and the back-end
servers.

For more information about Event ID 1000, visit the Microsoft
Events and Errors Message Center (EEMC) at the following Microsoft Web site:

This problem occurs when you use a disjointed DNS namespace.
For example, in a domain that is named "country.domain.com," you use a
fully-qualified domain name (FQDN) for the front-end server that resembles the
following name:

Feserver.Region1.country.domain.com

In this case, a request is made for a Kerberos Ticket in the domain "Region1.country.domain.com." However, this domain does not exist.

Information on adding the registry key is below. It can be added automatically using the Fix It button or manually by adding the key as described in the "Let me fix it myself" section.

Hotfix Information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:

Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

You must install Microsoft Exchange Server 2003 Service Pack 2
(SP2) before you apply the hotfix. For
more information, click the following article number to view the article in the
Microsoft Knowledge Base:

Restart requirement

You do not have to restart the computer after you apply the
hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

The global version of this hotfix has the file
attributes (or later file attributes) that are listed in the following table.
The dates and times for these files are listed in Coordinated Universal Time
(UTC). When you view the file information, it is converted to local time. To
find the difference between UTC and local time, use the Time
Zone tab in the Date and Time item in Control Panel.

To add the registry key automatically, click the
Fix it
button or link. Click
Run
in the
File Download
dialog box, and then follow the steps in the Fix it wizard.

Note: Because this change is related to a hotfix, you must install the hotfix in addition to running the Fix this problem wizard. If you only run the Fix this problem wizard and you haven't installed the hotfix, the problem will not be resolved.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

For more information about the terminology that Microsoft
uses for software that is corrected after it is released, click the following
article number to view the article in the Microsoft Knowledge Base: